Automatic switch



Oct. 19,1926. 1,603,897

H. P. BOSWAU AUTOMATIC SWI TCH -Filed July 10, 1924 2 Sheets-Sheet l ----[nuenlnr Hans E Busmau idle trunk leading to a connector s yitch, such as indicated by the reference charartcr H, depending on the size of the systen'i. Let us assume that the calling sub criber has established his connection up as far as the last selector, and that the selector has come to rest on its bank contacts which are connected to the conductors 3 and l of the connector H this connector being the first idle one in the two-ring connector "roup. lVhcn the selector switch comes to res upon he contacts associated with conductors 2 3 and it, the switching relay of the select completes an energizing circuit for the line relay 6 of the connector switch ll as fol.- lows: From ground by way of the lower winding of the line relay 6, normally closed contact controlled by ari'nature 15, line cenductor 4:, over the intervening switches and the subscribers loop back to line conductor 2, normally closed contact controlierl by armature ll, and through the upper winding; of relay 6 to l attery. Relay 6, upon energizing' closes a circuit for release relay 7 at armature l6. Relay '4, upon energizing; 1- nects ground to the release conductor 3 at arn'iature 17, said ground con'ipietinn a hol iing circuit for the switches back of the connector switch for i'naintainingr said switches in an operated position. and, in add tion. making the trunk line to the connector ll busy to all other selectors ha ing arc ss thereto. A further result of ti e energizertion of the relay 7 is the preparation ot a circuit for the yertical magnet 11 and the further opening of the release circuit armature 19, which circuits will be explained hereinafter.

The calling subscriber may now manipulate his calling: device in accordance with the next to the last digit in the number of the wanted subscriber. Due to the opcrdion of the calling device by the calling; subscriber the circuit of the line relay 6 is interrupted a number ot times correspond ing' to the digit dialled and the line relay. in response to these circuit interruptions. drenerg'izes duringan equal nnn bcr of short intervals. Relay 6, ipon deeuergizinm closes a circuit for the vertical magnet. 11 and the switching; relay 10 in parallel, From ground, armature 1G and contact, arma ire 19 and its the wipers inclusive. one step oppo site the first level of bani: contacts. Relay 10 is energized in parallel with the ver cal magnet 11 and closes a locking circuit for itself at armature S-i to ground at armature 1G, by way of armature 19 and rotary olt normal spring and being slow-acting: holds up continuously during; the \crtical operation of the switch. By the operation oi' this relay the vertical magnet circuit is d intact. notwithstanding the shiftal 0 iormal springs 37 and ii *ound, a1

Lia-.111 cont; ct, rn ature i9 and its worki ntact iCFtHrQ contact and rotary oftil) arniature 3 t and its rotary oil-normal s ine I contact. and magnet ll end of the yertical more- ,encrsi'izes and transfers the lll operat' k circuit to the rotary magnet 12.

The calling subscriber now transmits the final series of impulses of the called telephone llllllllJGl. Responsive to these interruptions the line relay 6 is deencrg ized a correspondi number of times and now sends i pul. to the rotary magnet, 12 over the following' circuit: from ground, armature 1t and its resting contact. armatur 19 and its working' contact. working; contacts controlled by vertical oft norma spring 37,

resting; contact and iature 33 resting contact and arinatr. 2i and rotary magnet 12 i re operation of the rotary i the wipers 5O inclusive, are d step by anti are finally brought c t in cement with the particular set is in which the line of subthe contacts being to ba Ev ii terminated. indicated in the drawing by reference charac cfs 'ifand The slow acting relay 9 is one izced in paral with the rotary magnet by way of armatu e 3 .1 and its rostinn; contact, at d remains continuously energized (llllll I "he rotary inoyenient. in operated posit on relay 9 connects the test wiper iii to the winding of the test relay 8 by means of its armature 25 and at armature 2. closes an alternative point in the circuit of the rotary ma; let, to guard against the DOS rig its circuit opened by ibility of ban the ope ation of the test relay while the test wipcr 51 is passing? over grounded test contacts.

The final series of impulses has received.

now been and he connector wipers l aye been placed in connection with the terminals of the called line. H the line is busy there will and the test relay 8 will be energized. lVhen this relay operates it prepares a locking circuit for itself at its armature 20, which is completed when the slow acting relay 9 falls back an instant later, opens the rotary magnet circuit at armature 21, and at armature 23 connects a lead from the busy signalling machine to the lower side of the line. On perceiving the signal, the subscriber will re place his receiver, thereby releasing the con nector H and all previously operated switches.

Assuming now that the called line is idle when connection therewith is attempted, under these circumstances there will be no ground on the test contact 54, and the test relay 8 will not be energized. Then when the slow acting relay 9 falls back a circuit is completed for the switching relay 10 which may be traced from the grounded conductor 8, armature 20 and its resting contact, upper winding of relay 10, resting contact and armature 25, resting contact and armature 31, test wiper 51, test contact 541-, switching relay 100 of the line switch C, and magnet 102 to battery. Relays 10 and 100 are energized in series over this circuit, but due to the usual mechanical interlocking device between the armature of the cut off relay 100 and the armature of line relay 101, the formcr is energized only half way and as a result the wipers of the called line switch C are not connected up, although line relay 101 and ground are disconnected from the called line.

In the connector H, when the switching relay 10 pulls up, it establishes a locking circuit for itself at armature 34L traceable from ground, working contact and armature 18, current drain lowering resistance 45, working contact and rotary oil-normal spring 40, arn'iature 34 and its working contact, and lower winding of relay 10 to battery. Further results of the energization of relay 10 are the grounding of the test wiper 51 at armature 31, the preparation of a holding circuit for relay 9 at armature 82, the opening of the rotary magnet circuit at armature 83, and the connecting up of the two wipers 50 and 52 at armaturcs 29 and 36. A still further result of the energization of relay 10 is the closing of a circuit for busy relay 8 (now functioning as a pick-up relay) at armature 3O traceable from grounc, wiper 42 of continuously rotating generator inter rupter 1, common pick-up conductor 4-7, working contact and rotary off-normal spring 41, armature 30 and its working contact, normally closed contact controlled by armature 20, normally closed contact controlled bv armature 25, and relay 8 to battery. Relay 8, upon energizing, closes a locking circuit for itself at armature 20 by way of ground at armature 17, and closes the ringing circuit at armature 22. Armature 22 is normally closed to battery so that the ringing relay 9 will energize to break the ringing current circuit in case the called subscriber lifts his receiver between the time connection is made with his line and ringing current is started; thus avoiding possible ringing in his ear. lVhen the wiper 42 of the interrupter I passes over the segn'ients connected with re ay 43, this relay energizes and deenergizes to cause two rings from the generator machine GEN. to be projected out intermittently over the called line to operate the bridged ringer at substation A to notify the called subscriber that he is wanted. The ringing circuit may be traced from ground, resting contact and armature 24, armature 29 and its working contact, wiper 50, contact 53, over the called subscribers loop and return to contact 55, wiper 52, working contact and armature 36, armature 2S and its resting contact. lower winding of relay 9, a -mature 22 and its working contact, and armature A and working contact to the generator machine GEN, the calling subscriber hearing the ringing by way of the condenser 48 and working contact and armature 35.

hen the called subscriber answers by lifting his receiver the ringing current bridge across the line is replaced by a direct current bridge, whereupon relay 9 is operated. Upon energizing, relay 9 closes a looking circuit for itself at armature 26 traceable from ground, working contact and armature l8. armature 26 and its working contact, current drain lowering resistance 46, working contact and armature 82, and upper winding of relay 9 to battery. Further results of the encrgization of relay 9 are the opening of the circuit of relay 8 at armature 25, where upon it deenergizes; breaking the ringing circuit at armatures 2i and 28; and at the working contacts of these same armatures the final completion of the talking connection.

Current is now supplied to the transm tter at substation A through the windings of the double wound back bridge relay 5 which is accordingly energized. This relay is a reversing relay and has the well known function of reversing the incoming trunk conductors 2 and 4- as regards their connections with the wind ngs of the relay 6. This reversing operation is a standard operation and is for the purpose of operating subscribers pay-stations or metering apparatus, and in some cases is used for supervisory purposes. The subscribers may new converse as desired.

At the end of the ensuing conversation, the two subscribers replace their receivers. The replacing of the receiver at the called subsation A stops current from flowing over its line and deenergizes relay 5, whereupon the conductors 2 and 4 are reversed with respect to the windings of relay 6. The replacing of the receiver at the callingsubstw tion (not shown) stops current from flowing over its line and deenergizes relay 6, whereupon the circuit of the release relay 7 is broken, and a circuit for the release magnet 13 is prepared at armature 1G. Relay 7, upon deenergizing, removes ground from the release trunk conductor 3 at armature 17, whereupon the preceding switches are released in the well known manner. A tur t'her result of the dcenergization of relay 7 is the opening of the locking circuits of relays 9 and it) at armature 1S, allowi g said relays to release, whereupon the latter relay opens the locking circuit of relay 1.00 at armature 31 and allows switch (1 to restore to normal condition. A still further result of the deenere'ization of relay 7 is the closing of a circuit tor the release magnet 13 at armature 19, thus allowing the switch H to return to normal. The release magnet 13 is energized over the following path: from gl'reun'l at armature 16 and its resting contact. armature 19 and its resting contact, vertical oil normal spring 38 and its working contact, and magnet; 13 to battery. The release magnet is maintained energized over the above traced circuit until the shaft and wipers are returned to their normal position, whereupon the circuit of the release magnet is opened by the separation at the verical ott normal springs.

An explanation will now be given of the ooeration oi the system when the connector Fig. 2, is substituted for the connector .l, fig. 1. Let us assume that the calling 'ubscriber has established his connection up far as the ast selector (not shown) and that the selector has come to rest on its bank contacts which are connected to the conductors 112, 113 and 114 of the connector 11, this connector being the first idle one accessible to said selector. Then the selector switch comes to rest upon the contacts associated with conductors 112, 113 and 114, the switching relay of the selector completes an energizing circuit for the line relay 116 of the connector switch H as follows: "from ground by way of the lower winding 01 line relay 116, normally closed contact controlled by armature 128, line conductor 114, over the intervening switches and the calling subscribefis loop back to line conductor 112, normally closed contact. controlled by armature 127, and through the upper winding of relay 116 to battery. Relay 11G, upon energizing, closes a circuit for release relay 117 at armature 129. Relay 117, upon energizing, connects ground to the release conductor 113 at armature 1531, said ground completing a holding circuit tor the switches back of the connector switch l'or maintaining said switches in an operated position, and, in addition, making the trunk line leading to the connector H busy to all other selectors having access thereto. Further results of the energizaof relay 117 are the preparation of a locking circuit for ringing and switching relays 119 and 122 at armature 130, and the preparation of a circuit for the vertical mag net 123, and the further opening of the release circuit at armature 132, which cir cuits will be explained hereinafter.

The calling subscriber may now manipulate his calling device in accordance with the next from the last digit in the number of the wanted subscriber. Due to the operation of the calling device by the calling subscriber, the circuit of the line relay 11(3 interrupted a corresponding number of times, whereupon said relay is momentarily deenergized a plurality of times and at each dcenergization transmits an impulse of cur rent to the vertical magnet over a path which extends from ground by way of armature 129 and its resting contact, armature 132 and its working contact, resting contact and off normal springs 158, winding of the slow to release series relay 11S, and the inding o1 the vertical magnet 123 to battery. By the operation 01 the vertical magnet the wipers 170172, inclusive, are raised step by step until they stand opposite the desired level of bank contacts. Relay 118 is energized in series with the vertical magnet 123 and being slow to release holds up cont nuously during the vertical operation of the switch. By the operation of this relay, the vertical magnet circuit is preserved intact, notwithstanding the shitting of the off-normal springs, which occurs at the first vertical step ot the switch. At the end of the vertical movement, relay 118 deencrgizes and transfers the operating circu t to the rotary magnet 124.

The calling subscriber now transmits the final series of impulses of the called telephone number. Responsive to these interruptions the line relay 116 is again deenergized a corresponding number of times and now sends impulses to the rotary magnet 12st over the following circuit: from ground by way of armature 129 and its resting contact, armature 132 and its working contact, resting contact and normally open contact controlled by oft normal spring 15",, armature 133 and its resting contact, resting contact and armature 141, resting contact and armature 150, and the winding of the rotary magnet 1241- to battery. By the operation of the rotary magnet. the wipers 170172, inclusive, are rotated step by step and are finally brought to rest in engagement with the particular set of bank contacts in which the line of the anted subscriber is terminated, these contacts being indicated in the drawing by reference char acters 173, 174 and 175. The slow to release relay 121 is energized in parallel with the rotary magnet and remains continuous ly energized during the rotary movement. In operated position, relay 121 connects the test wiper 171 to the winding of the test relay 120 by means of its armature 148, and at armature 14:4: closes an alternative point in the circuit of the rotary magnet to guard against the possibility of having this circuit opened by the operation of the test relay while the test wiper 171. is passing over grounded test contacts.

The final series of impulses has now been received, and the connector wipers have been placed in connection with the terminals oi the called line. If the line is busy there will be a ground potential on the test contact 17 1 and the test relay 120 will be energized. When this relay operates it propares a locking circuit for itsel'l at its armature 138, which is completed when the slow to release relay 121 falls back an instant later; opens the rotary magnet circuit at arn'iature 1e11, and at armature 1 12 connects a lead from the busy sigi'ialling machine to the lower side of the line. @n pcrceiving the signal, the subscriber will replace his receiver, thereby releasing the connector 11 and all previously operated switches in the usual well known manner.

Assuming now that the called line is idle when connection therewith is attenuated, under these circumstances there will be no ground on the test contact 17 1, and the test relay 1:20 will not be energized. Then when. the slow to release relay 121 falls back. a circuit is completed for the switching relay which may be traced from ground by way of armature 131 and its working contact, armature 138 and its resting contact, lower winding of the switching relay 122, resting contact and armature 1 13, test wiper 171, test contact 174, and winding of the cut-otl' or switching relay of the line switch (not shown) to battery. Relay 122- and the cut oil relay of the line switch are energized in series over this circuit, and the latter relay operates to clear the line conductors of their normal battery and ground connections in the line switch.

At the connector H when the twitching relay 122 pulls up it establishes a locking circuit for itself at armature 1418, grounds the test wiper 171 at armature 1417, opens the rotary magnet circuit at armature 150, connects up the two line wipers 170 and 172 at armatures 1 15 and 152, and at armature 1419 prepares a circuit for busy relay 120 (now functioning as a pick-up relay) which may be traced as follows: from ground by way oi wiper 155 of the continuously rotating generator interrupter 1 common pick up conductor 158, normally closed contact controlled by armature 14:0, resting contact and armature 136, working contact and armature 14-9, and winding of relay 120 to battery. Relay 120, upon energizing, closes a locking circuit for itself at armature 140 by way of ground at armature 131, and closes the ringing circuit at armature 139. Armature 1259 is normally closed to battery so that the ringing relay 119 will energize to break the ringing current circuit in case the called subscriber lifts the receiver between the time connection is made with his line and ringing current is started; thus avoiding possible ringing in his ear. l Vhen the wiper 155 of the interrupter 1 passes over the segments connected with the interrupter relay 156, this relay energizes and deenergizes to cause two rings from the generator machine GEN. to be projected out intermittently over the called line to operate the bridged ringer at the called substation to notify the subscriber that he is wanted. The ringing circuit may be traced from ground by way of armature 137 and its resting contact, armaturc 152 and its working contact, wiper 172, bank contact 175, through, the ringer and condenser at the called substation (not shown) and back to the bank contact 173, wiper 170, working contact and armature armature 13d and its resting contact, lower winding of the ring cut ofi relay 119, a" ature 1259 and its working contact, and armature 157 and its working contact to the generator machine GEN. Relay 119 being marginal will not operate in series with the ringer and condenser at the called substation. The ringing of the called sub-- scriber s )Qll continues intermittently until he answers by removing his receiver from the switchhook, or the calling subscriber abandons the call and restores his receiver, the calling subscriber receiving the usual well. known ringing tone by way of armature i l-.6 and condenser 159, as long as the ringing continues and he holds the receiver to his car.

When the called subscriber answers, a direct current bridge is closed across the conductors of the line, thereby operating relay 119. This circuit may be traced over the same path as for the ringing current, except for the direct current bridge at the substation, up to and including armature 157 where it continues by way of its resting contact to battery, in case the receiver is removed during the silent period, or through the generator to battery it the receiver is removed during a ringing period. Upon energizing, relay 119 closes a locking circuit for itself at armature 135 by way of ground at armature 130 and its working contact; opens the locking circuit of relay 120 at armature 136, whereupon said relay deencrgizes and restores its armatures to normal condition; and at arinatures 134 and 137 disconnects the wipers 170 and 17 2 from its own lower winding and ground, respectively, and extends them to the windings of the back bridge relay 115. Relay 115 is operated and reverses the battery to the calling party, so that a meter or coin collector can be operated at the calling station, if desired. The calling and called subscribers may now converse with each other as desired, the talkin circuit being outlined by the heavy conductors.

At the end of the ensuing conversation, the two subscribers replace their receivers. The replacing of the receiver at the called substation stops current from flowing over its line and deenergizes relay 115.

Nhen the receiver is replaced at the cal.- ing substation, the circuit of the line relay 116 is opened and it deenergizes. Upon armature 129 being retracted the circuit of release relay 117 is opened, while a circuit is prepared for the release magnet 125. Relay 117, upon deenergizing, disconnects ground from the release trunk conductor 113 at armature 131, whereupon the preceding switches are restored to normal condition. A further result of the deenergization of relay 117 is the opening of the locking circuits of relays 119 and 122 at armature 130, whereupon said relays deenergize and restore their armatures to normal condition. A still further result of the deencrgization of relay 117 is the closing of a circuit for release magnet 125 at armature 132 by way of oil normal spring 154: and its working contact, whereupon said magnet operates to restore the wipers of the connector H to normal position. lVhen the wipers reach their normal position the circuit of release magnet 125 is again opened at oll' normal spring 15a by the switch shaft in the usual well known manner.

The invention having been fully described, what is considered new and is desired to have protected by Letters Patent will be pointed out in the appended claims.

What is claimed is:

1. In a telephone system, a connector switch, wipers for said switch, a vertical magnet in said switch for stepping said wippers vertically, a switching relay in said switch, circuit means for operating said switching relay in parallel with said vertical magnet, means whereby said switching relay is made slow acting so that it is held operated during the vertical stepping of said wipers to maintain the operating circuit of said magnet intact, a rotary magnet lor stepping said wipers to a called line, and contacts on said switching relay for closing the ringing circuit to said wipers when the called line is connected with.

2. In a telephone system, a connector switch, wipers for said switch, a vertical magnet in said switch for stepping said wipers vertically, a switching relay in said switch, circuit means for operating said switching relay in parallel with said vertical magnet, means whereby said relay is made slow acting so that it is held operated during the vertical stepping oi said wipers to maintain the operating circuit of said vertical magnet intact, said switching relay being released upon completion of the vertical stepping thereby breaking the operating circuit of said vertical magnet, a rotary magnet for stepping said wipers to a called line, and contacts on said switching relay for closing the ringing circuit to said wipers when the *alled line is connected with.

In a telephone system, a connector switch, wipers for said switch, a rotary magnet in said switch, a ring cut oil relay in said switch, a circuit for operating said ring cut oil relay in parallel with said rotary magnet, means for intermittently closing said circuit to cause said magnet to rotate said wipers, and means whereby said ring cut oil relay is made slow acting so that it is held operated during the rotary motion of said wipers to maintain the operating circuit oi said magnet intact.

a. In a telephone system, a connector s vitch, test and line wipers for said switch, a rotary magnet in said switch for rotating said wipers horizontally, a ring cut oil relay in said switch, circuit means for operating said ring cut oil relay in parallel with said rotary magnet, means whereby said ring cut oil relay is made slow acting so that it is held operated during the horizontal stcp ping of said wipers to maintain the operat ing circuit oi said rotary ma net intact and is released upon completion or the horizontal stepping, a test relay in said switch, and a circuit controlled by said ring cut off relay for energizing said test relay before said ring cut oil relay deenergizcs if said test wiper finds ground at the end of its horizontal stepping.

5. In a telephone system, a connector switch, test and line wipers for said switch, a rotary magnet is said switch for rotating said wipers horizontally, a ring out otl relay in said switch, circuit means for oper ating said ring cut oil relay in parallel with said rotary magnet, means whereby said ring cut oil relay is made slow acting so that it is held operated during the horizontal stepping of said wipers to maintain the operating circuit of said rotary magnet intact, a switching relay in said switch, and means whereby said switching relay is operated responsive to the deenergization of said ring cut oil relay it said test wiper finds battery at the end of its horizontal stepping.

The combination, with an automatic vertical and rotary switch for connecting with a line, of a con'ibination vertical control and switching relay, said relay having normally open contacts for maintaining the operating ci cuit of the vertical magnet intact during llO the vertical movement and for connecting up the switch wipers upon being connected with an idle line, and vertical and rotary oft normal springs for controlling the said relay.

7. The combination, with an automatic vertical and rotary switch for connecting with a line, of a combination rotary control and ring cut oil? relay, said relay having normally open contacts for maintaining the operating circuit of the rotary magnet intact during the rotary movements and having contacts for opening the ringing circuit when the receiver is removed at the called substation.

S. The combination, with an automatic code ringing switch for connection with a party line and signalling a station on said line, of a combination busy test and pick up relay means for energizing said relay when the switch connects with a busy line and contacts on said relay for completing the code ringing circuit at the proper time so as not to mutilate same when the switch connects with an idle line.

9. A connector switch having primary and secondary movements, means for chang ing over from primary to secondary movement, means for connecting the switch wipers when the secondary movement is completed, and a single magnet for controlling said change-over means and said connecting means, said magnet controlling the primary movement when energized and the second ary movement when deenergizech 10. In a connector switch, a test relay, a switching relay, a test wiper, contacts for connecting said wiper to either of said relays, a ringing circuit, contacts for breaking said ringing circuit when a called party answers, and a single relay for operating all said contacts.

11. In a connector switch, a test relay, a test wiper, contacts for connecting said wiper with. said relay while the switch is being operated to connect with a line and for breaking the connection after the line is connected with, a ringing circuit, contacts for breaking said ringing circuit when the called party answers, and a single relay for operating all said contacts.

12. In a two motion connector switch, a combination secondary control and ring out ofi" relay, means for maintaining said relay energized during the secondary movement of said switch to control the test circuit thereof, said relay being deenergized when the secondary movement is completed, a ringing circuit for signalling the called line, and means for energizing said relay to break said ringing circuit when the called party answers.

13. In a connector switch, a combined test and pick-up relay, means for energizing said relay to signal the calling line it the called line is busy when connected with, means for preparing a code ringing circuit it the called line is idle, and means for energizing said relay to complete said ringing circuit.

14. In a telephone system, a connector switch, test and line wipers for said switch, a rotary magnetin said switch for rotating said wipers horizontally to select a line, a ring cut-off relay in said switch, circuit means for operating said ring cut-off relay in parallel with said rotary magnet, means whereby said relay'is made slow acting so that it is held operated during the horizon tal stepping of said wipers to maintain the operating circuit of said rotary magnet intact, a switching relay in said switch, and means whereby said switching relay is operated responsive to the deenergization of said ring cut-oil relay it said test wiper finds the selected line to be idle.

15. In a connector switch, a combination busy test and ringing circuit control relay, contacts on said relay for closing a busy signalling circuit when the connector connects with a busy line, and contacts on said relay for closing the ringing circuit when said connector connects with an idle line.

In witness whereof, I hereunto subscribe my name this fifth day of July, A. D., 1924.

HANS P. BOSi VAU. 

